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Pyrazolones derivatives are known for their pharmaceutical and therapeutic activities. In this regard, some new pyrazolone derivatives have been synthesized using cyclocondensation, nucleophilic substitution, and alkylation reactions. Their corresponding structures were elucidated using X-ray diffraction and NMR spectroscopic techniques. The experimental spectral data were compared with the predicted ones obtained at the B3LYP/6-311++G(d,p) level of theory. Geometrical parameters and chemical shifts are relatively well reproduced with correlation coefficients higher than 90%. The intercontacts in crystal units were investigated by the analysis of their corresponding Hirshfeld surfaces and fingerprint maps, which reveal that the major contacts are found for H...H intercontacts. Finally, the inhibition efficiency of the novel pyrazolone derivatives as SARS-CoV-2 Mpro is estimated by determining their binding affinities into the binding site of SARS-CoV-2 Mpro. The docking results reveal that the current pyrazolone derivatives may act as potent inhibitors of SARS-CoV-2 Mpro and that their inhibition efficiency may be strongly influenced by the substituted functional groups of pyrazolone moiety. Synthesis of new 4-Substituted Pyrazolone derivatives Good correlations are obtained between the spectra and X-ray data with the predicted ones. Hirshfeld surface analysis is used to analyze intermolecular interaction. 3D molecular structure is characterized using x-Ray and spectroscopic techniques. Interactions for of the newly synthesized compounds 2b, 3b, 3a, and 4 docked SARS-CoV-2 Mpro/PDB: 6LU7-A chain protein. [ABSTRACT FROM AUTHOR]

The incorporation of the piperidine ring into drugs may play an interesting role to fulfill significant tasks and act as an active ingredient in various treatments. Herein, three novel derivatives of 3‐acetyl‐2‐hydroxybenzoic acid (3‐5) containing a piperidine ring were synthesized through the rearrangement of triacetic acid lactone in the presence of piperidine. Their molecular structures were characterized by 1H and 13C NMR and single crystal X‐ray diffraction techniques. The experimental data were compared with the predicted ones obtained in the polarizable continuum model at the B3LYP/6‐311++G(d,p) level of theory. Relatively good correlations were obtained between the experimental data (spectral and Z‐matrix coordinates) and the predicted ones, with correlation coefficients higher than 97%. The intercontacts between the closest units of 3‐5 were identified through the analysis of the Hirshfeld surface and electrostatic potentials (ESP) maps. Hirshfeld surface and ESPs analyses reveal that the closest interactions between the units of the compounds are between hydrogen atoms (59%‐67%). The antioxidant activity of 3‐5 was evaluated using DPPH free radical scavenging and ABTS assays. They exhibit moderate antioxidant activity, which probably is attributable to the presence of a phenolic moiety in their basic skeleton. Molecular docking calculations suggest that 3‐5 may mainly bind to the active binding site of peroxiredoxin 5 through strong and weak intermolecular hydrogen bonds. [ABSTRACT FROM AUTHOR]

A new series of substituted benzoylthiourea derivatives namely N -(4-methoxybenzoyl)- N '-(3-hydroxyphenyl)thiourea (1a), N -(3-methoxybenzoyl)- N' -(3-hydroxyphenyl) thiourea (2a), N -(3-nitrobenzoyl)- N' -(3-hydroxyphenyl)thiourea (3a) and N -(4-phenylbenzoyl)- N' -(3-hydroxy phenyl)thiourea (4a) bearing phenolic groups were efficiently synthesized from the condensation reaction of benzoylisothiocyanate with 3-aminophenol. The molecular structures of 1a-4a are elucidated by FT-IR, UV–Vis, 1H and 13C NMR spectroscopic techniques. The four benzoylthiourea derivatives were obtained in crystalline forms by recrystallization in DMSO. X-ray chemical crystallographic study shows that 1a crystallizes in triclinic crystal system, while 2a - 4a crystalize in monoclinic crystal system. The synthesized benzoylthiourea molecules adopt trans-cis configuration with respect to the positions of carbonoylbenzoyl and 3-hydroxyphenyl groups respectively, against the thiono C=S bonds across their C–N bonds. The corresponding predicted z-matrix coordinates and spectral data of 1a - 4a were obtained using DFT and TD-DFT methods. The quantum chemical calculation have been carried out using three hybrid functionals B3LYP, B3P86 and PBE0 combined with 6–31++G(d,p) basis set. The solvent effects were taken into account implicitly using IEF-PCM model. The experimental Z-matrix coordinates and the spectral data of the tilted compounds are relatively well reproduced with good correlations coefficients. Image 1 • Synthesis of a new series of substituted benzoylthiourea derivatives. • X-ray crystallographic studies show that benzoylthiourea derivatives adopt trans-cis configurations. • The excited sites are relatively well reproduced using PBE0 hybrid functional. [ABSTRACT FROM AUTHOR]

A novel derivative of pyrimidine containing the 1,2,4-triazolo[1,5-a]pyrimidine ring has been synthesized by means of a condensation reaction of 3-amino-1,2,4-triazole with 4-hyroxy-6-methyl-pyran-2-one. The resulting structure of 2-(4-vinylbenzyl)-2-(5-methyl-[1,2,4]triazolo[1,5-a]pyrimidin-7-yl)-3-(4-vinylphenyl)propanoate, C 10 H 12 N4O 2 , (3), has been characterized by X-ray single crystal diffraction (XRD) and a variety of selected spectroscopic techniques (1H NMR, 13C and IR). The geometrical parameters and spectral data of 3 were also compared with those of a DFT geometry optimization and molecular orbital calculation utilizing the B3LYP/6-31 + G(d,p) level of theory in PCM. The intermolecular contacts in 3 were then investigated by analysis of its Hirshfeld surface along with ESP maps. The antibacterial activity of 3 against Gram positive and Gram-negative microbial strains such as Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were evaluated with results showing antibacterial activity of 3 with respect to a MIC reference. Image 1 • Synthesis of a novel derivative of 1,2,4-triazolo[1,5-a]pyrimidine derivative. • 3D molecular structure is characterized using x-Ray and spectroscopic techniques. • Good correlations are obtained between the spectra and Xx-ray data with the predicted ones. • The synthesized compound shows significant antibacterial activity. [ABSTRACT FROM AUTHOR]

Abstract Two new (4 – 5) and a known (3) derivatives of 1,2,4-triazolo [1,5-a]pyrimidine are synthesized and characterized through spectroscopic NMR, FT-IR and single crystal X-ray diffraction techniques. Along with experimental data, the predicted spectral data are obtained using density functional theory (DFT) at the B3LYP/6-31 + G (d,p) level of theory. The closest contacts between active atoms of the compounds are identified through Hirshfeld surface analysis and electrostatic potential map (EPM) studies. Relatively, good correlations were found between the experimental and predicted spectroscopic data with correlation coefficients higher than 90%. Hirshfeld surface analysis and EPM reveal that the closest interaction between the units of the compounds are between hydrogen atoms (39.6–46.3%). The antioxidant activity of 3 – 5 is evaluated using DPPH free radical scavenging and ferric reducing antioxidant power assays. Graphical abstract Image 1 Highlights • Synthesis of two new and one known derivatives of 1,2,4-triazolo [1,5-a]pyrimidine derivatives. • 3D molecular structures are characterized using X-Ray and spectroscopic methods. • DFT calculations at B3LYP allow a better reproduction of the experimental data. • The antioxidant activity is evaluated using DPPH free radical scavenging and ferric reducing antioxidant power assays. [ABSTRACT FROM AUTHOR]

• Synthesis of new 1,2,3-triazol-3-(substituted)-benzoimidazol-2-one derivatives. • 3D molecular structure is characterized using x-Ray and spectroscopic techniques. • The Hirshfeld surface analysis was used to analyze the intermolecular interaction. • DFT and Monte Carlo simulations support the obtained inhibition efficiency of new 1,2,3-triazole. • Antibacterial activity was performed using two different methods such us agar disc diffusion method and Minimum inhibitory concentration (MIC) method. A new series of 1,4 and 1,5-disubstituted-1,2,3-triazole derivatives containing a benzimidazolone moiety [(3a-3b), (4a-4b), (5a-5b) and (6a-6b)] were synthesized using 1,3-dipolar cycloaddition in toluene under thermal conditions with N-alkyl, N-propargyl- benzimidazolones as dipolarophiles and azide derivatives as dipoles. Furthermore, the 1,4-disubstituted-1,2,3-regioisomers (3a-6a) have been also obtained exclusively using click chemistry (Copper-Catalyzed Azide-Alkyne Cycloaddition). The structures of all compounds were characterized by 1H-and 13C-NMR spectroscopy. The molecular and crystal structures of three compounds (3a, 4a, and 5a) were confirmed by single crystal X-ray crystallography. In addition, Density Functional Theory (DFT) was used to predict spectral data at the B3LYP/6-31G (d, p) level. Intermolecular interactions in the crystals of 3a, 4a, and 5a were determined by Hirshfeld surface analyses and the Monte Carlo method was used to investigate the interfacial interactions of these derivatives with iron, copper, and aluminum surfaces. Based on the Monte Carlo results, the new compounds can provide better anti-corrosion properties for iron as compared to copper and aluminum. The expected inhibition efficiency is 5a > 3a > 4a, which is attributed to the favorable effect of the lateral carbon chain of the triazole moiety in this process. The antibacterial activities of 1, 2, 3a, 3b, 4a, 5a, 5b, 6a, and 6b against Gram-positive and Gram-negative microbial strains, such as Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa were evaluated, and the results obtained showed antibacterial activities for all of them using a minimum inhibitory concentration (MIC) test. The molecular structures with atom labelling schemes and 50% probability ellipsoids for 3a, 4a and 5a [Display omitted] [ABSTRACT FROM AUTHOR]

A novel compound named 2-methyl-3 H -benzimidazolo[1,2-b][1,2,4]triazepin-4(5 H)-one (C 11 H 10 N 4 O) has been synthesized and characterized by spectroscopic techniques (FT-IR),UV–Vis,1H NMR, 13C NMR and mass spectra. The optimized molecular structure analyses, vibrational wave numbers, 13C and 1H NMR chemical shifts of the title molecule have been performed at DFT/B3LYP method with 6-31 + G(d,p) basis set. The electronic absorption wavelengths computed using B3LYP, B3P86 and PBE0 hybrid functional. The scaled vibrational modes, and the predicted 13C NMR and 1H NMR chemical shifts are relatively in good agreement with the corresponding experimental ones. However, B3LYP, B3P86 and PBE0 hybrid functional fail in reproduction of experimental λ MAX of the tilted compound and it is underestimated by the tested hybrid functionals with deviations to the experimental values of 30, 34 and 40 nm for B3LYP, B3P86 and PBE0, respectively. In addition, molecular docking and molecular dynamics simulations of titled compound were carried out to determine its binding modes and stability within the leucine-rich repeat kinase 2 active site. Image 1 • 2-Methyl-3 H -benzimidazolo[1,2- b [1,2,4]triazepin-4(5 H)-one was synthesized and characterized. • Molecular structure is characterized by using spectroscopic techniques. • DFT calculations at B3LYP allow a better reproduction of the experimental data. • Molecular docking and molecular dynamics analysis were carried with leucine-rich repeat kinase 2 complex. [ABSTRACT FROM AUTHOR]

• Pyrazole derivative was synthesized and characterized by FT-IR, 1H NMR, 13C NMR ESI-MS and X-ray diffraction. • Theoretical structures of the title compound were optimized using B3LYP/6–31+ G (d,p) calculations. • Hirshfeld and MEP surfaces studies were carried out. • The title compound was also evaluated for their α-glucosidase and α-amylase inhibition. • Molecular docking studies were carried out to understand the binding mechanism of the title molecule and α-glucosidase-3W37 and α-amylase-1B2Y receptors. In this work, a novel crystal i.e. (E)- N' -(4-chlorobenzylidene)-5-phenyl- 1H -pyrazole-3-carbohydrazide has been synthesized and characterized using various spectroscopic techniques. The (E)-configuration of the azomethine (N CH) was confirmed by single crystal X-ray analysis. The molecule crystallizes in the monoclinic space group, P21/c, a = 15.629(9) Å, b = 7.152(4) Å, c = 14.707(9) Å, β = 111.061(15)°, V = 1534.1(6) Å3 and Z = 4. In addition, the elucidated molecular structure was confirmed by comparing the predicted Z-matrix geometries and spectroscopic data with the experimental ones. DFT calculations have been carried out in gas and IEFPCM solvent at the B3LYP/6–31+ G (d,p). The in vitro anti-diabetic potential of the title compound was evaluated against α-glucosidase and α-amylase enzymes. Molecular docking studies showed that the various interactions tightly anchored the title compound to the active site, which makes it a more potent α-glucosidase inhibitor compared to well-known Acarbose. [Display omitted] [ABSTRACT FROM AUTHOR]

• Synthesis of three new long-chain alkyl-substituted 1,4-benzothiazine derivatives. • 3D molecular structures were characterized using X-ray and spectroscopic techniques. • Hirshfeld surface analysis was carried out used to study the intermolecular interactions. In this work, three novel long-chain alkyl substituted 1,4-benzothiazine derivatives have been synthesized by alkylation reactions under phase transfer catalysis conditions. The obtained compounds (4, 5 and 6) obtained were characterized using 1H- and 13C- NMR spectroscopy and X-ray. Their molecular and crystal structures have been determined by single-crystal X-ray diffraction techniques. The experimental data, were compared with the predicted ones spectral data were also obtained using density functional theory (DFT) at the B3LYP/6-31G(d,p) level of theory. In addition, the closest contacts between the active atoms of the compounds were identified through Hirshfeld surface analyses. According to Monte Carlo simulations, the new compounds can act as good corrosion inhibitors for iron and as moderate ones for copper and aluminum metals. [ABSTRACT FROM AUTHOR]

Four benzaldehyde thiosemicarbazone derivatives namely as 2-benzylidene- N -phenylhydrazinecarbothioamide (L1), 2-(4-hydroxybenzylidene)- N -phenylhydrazinecarbothioamide (L2), 2-(4-chlorobenzylidene)- N -phenylhydrazinecarbothioamide (L3), and 2-(4-methylbenzylidene)- N -phenylhydrazinecarbothioamide (L4) were successfully synthesized and elucidated by physical and spectral techniques, to be specific, melting point, elemental analysis (CHNS), infrared spectroscopy (FTIR) and 1H and 13C nuclear magnetic resonance spectroscopy (NMR). These organic corrosion inhibitors behaviour for mild steel (MS) in 1.0 M HCl solution was examined using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. From the electrochemical measurements, most ligands behave as efficient inhibitors for the MS in 1.0 M HCl solution which contribute the maximum inhibition efficiency up to 93.38% for L3. The potentiodynamic polarization measurements unfolds each synthesized compound were mixed-type inhibitor based on the shifting of corrosion potentials (E corr) found to be lesser than ±85 mV. The electrochemical impedance spectroscopy (EIS) analysis revealed retardation of metal corrosion succeeded by cause of adsorption of the four thiosemicarbazone derivatives inhibitor molecules at the metal/solution interface. The adsorption of thiosemicarbazone molecules on the low carbon steel surface in 1.0 M HCl solution obeys Langmuir adsorption isotherm. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) demonstrates in the presence of optimum concentration of L1-L4 inhibitors at 0.04 mM indicates greatly reduced surface roughness of MS in comparison with uninhibited solution. The findings were further reinforced via surface elemental analysis of metal/solution interface via X-ray Photoelectron Spectroscopy (XPS), which unveils L3 exhibit the greatest inhibition efficiency. The most plausible reason is due to benzene rings in the molecular structure increases the adsorption ability in supporting the substituent of chloro as well as conjugated double bond of C=N and C=S that chemisorbed along the surface of metal. The oxide species of FeO, Fe 2 O 3 and FeOOH found to be chemisorbed and physisorbed on MS surface. The impact of molecular properties on the corrosion inhibition and the adsorbed sites of L1-L4 on the metal were investigated using density functional theory calculations (DFT) at the B3LYP/6–311 + G (d,p) level of theory. From the Frontier Molecular Orbitals (FMO), the Highest Occupied Molecular Orbitals (HOMO) discloses adsorption of L2 on the MS surface generally due to 2-(4-hydroxybenzylidene)- N -hydrazinecarbothioamide, whereas for L1, L3 and L4 associated to the inclusion of phenyl carbothioamide. The Lowest Occupied Molecular Orbitals (LUMOs) of L1-L4 are comparatively resembling and delocalized of all molecules. DFT reveals protonated thiosemicarbazones exhibits high correlations coefficients as up to 99–100% in comparison to the corresponding neutral forms of the molecules. The increase in the inhibition efficiency of protonated L1, L2 and L3 is proportional to the ∆N and DM. • Thiosemicarbazones show efficient corrosion inhibition in 1.0 M HCl solution. • X-ray photoelectron spectroscopy reveals the adsorption forms. • Molecular orbital delocalization explains the adsorption of thiosemicarbazones. [ABSTRACT FROM AUTHOR]

• An efficient process was described to prepare a novel 6‑bromo‑2‑chloro‑3-butylquinazolin-4(3 H)-one. • The targeted compound was assessed for anti-bacterial activity. • Single crystal XRD structural studies of the 6‑bromo‑2‑chloro‑3-butylquinazolin-4(3 H)-one was performed. • Hirshfeld surfaces and their associated two-dimensional fingerprint plots were used to analyze the intermolecular interactions. An efficient process was described to prepare a novel 6‑bromo‑2‑chloro‑3-butylquinazolin-4(3 H)-one. The targeted compound was synthesized from available chemicals and assessed for anti-bacterial activity. This new compound structure crystallises in the triclinic system with P -1 space group. Its unit cell parameters are (a = 4.91550(10) Å, b = 11.4764(2) Å, c = 12.1670(3) Å), volume (638.11(4) Å3), α= 110.079(8)°, β= 93.8130(10)°, γ = 95.4580(10)° and Z = 2. The crystal packing was stabilized by C = O ...H hydrogen bonds and CH 3 CH 2 CH 2 CH 2 CHH....C π-stacking interaction and hydrogen π-π stacking interactions. Hirshfeld surfaces and their associated two-dimensional fingerprint plots were used to analyze the intermolecular interactions in the crystal structure. In addition, electrostatic surface potential (ESP) was generated using the density functional theory. [ABSTRACT FROM AUTHOR]

In this work, the synthesis, spectroscopic characterization and crystal structure of the [Ir(2,4-F 2 ppy) 2 (pyta)Cl] complex are presented. Remarkably, this Ir(III) complex exhibits a blue-green emission (λ em = 469 nm) at room temperature. TD-DFT calculations have been performed to derive a simulated absorption spectrum and vertical excitation energies. • Our group is focusing on a synthesized [Ir(2,4=F 2 ppy) 2 (pyta)Cl] complex. • Characterization of the Ir(III) complex was done by NMR, FTIR, UV–Vis and LC-QTOF/MS. • Molecular structure of Ir(III) complex was determined by single crystal XRD technique. • Photophysical studies and DFT calculations on Ir(III) complex have been performed. The cyclometallated Ir(III) complex [Ir(2,4-F 2 ppy) 2 (pyta)Cl], where ppy and pyta denote 2-phenylpyridine and pyridine-triazole respectively, was successfully synthesized by the reflux reaction of the 2-(1H-1,2,4-triazol-1-yl)pyridine ligand with the Ir(III) dimer [Ir(2,4-F 2 ppy) 2 (µ-Cl)] 2. The Ir(III) complex were characterized by spectroscopic methods: NMR, FTIR, UV–Vis and LC-QTOF/MS, while the molecular structure was determined by the single crystal X-ray diffraction technique. The X-ray crystallographic study revealed that the Ir(III) ion was coordinated to one pyridine-triazole, one chloro and two difluorophenylpyridine ligands in a distorted octahedral geometry. Steady-state emission spectroscopy demonstrated that the Ir(III) complex emitted blue-green light in dichloromethane solution with an emission maximum at 469 nm due to the admixtures of 3LC and 3MLCT character excited states. DFT calculations on the Ir(III) complex showed that the HOMO was localized predominantly over the cyclometallating ligands and the Ir 5 d orbitals, whilst the LUMO was located on both cyclometallating ligands, with the HOMO-LUMO energy gap being 3.86 eV. The intercontacts between different units of the cyclometallated Ir(III) complex were investigated by analyzing the Hirshfeld surface and molecular electrostatic potential surface plotted in the ground and triplet excited states. The X-ray structure of the Ir(III) complex was relatively well reproduced with B3LYP/LANL2DZ level of theory, where the two structures, experimental and theoretical, were well superposed. The calculated ground and triplet excited states geometries showed slight differences. [ABSTRACT FROM AUTHOR]